Document 6wdBnByg5w0034k34bxxvjXD4

FILE NAME Kelly Moore KM DATE 1975 June 24 DOC KM025 DOCUMENT DESCRIPTION Union Carbide Report - Comparison of Airborne Asbestos Concentrations - Canadian and California Asbestos Based Ceiling Texture Sprays with Cover Letter Sent to Paco Textures Co. UNION CARBIDE | | THE DISCOVERY COMPANY Calidria ASBESTOS Calidria MINING & METALS DIVISION * P.O. BOX 579 NIAGARA FALLS N. Y. 14302 +) TEL 716-278-3376 * = UNION CARBIDE CORPORATION July 7 1975 Mr. Doug Merrill Technical Director Paco Textures Company 909 Old County Road San Carlos CA 94070 Dear Doug report of our regular dust count for the Los Gatos A copy tests is enclosed I understand that you have already received the of the LFE tests from Dr. Oberg spraying results be interested in the report Comparison of Airborne Asbestos You may Based Ceiling Texture Sprays which Concentrations - Canadian and California of the results prepared is a more detailed analysis is also enclosed This to the Marks bill in conjunction with our efforts to get amendments Thank you very much for the time associations to make it possible to obtain and effort made this data by you and your Very truly yours HBR cjb Enclosures CC Mr. T. P. Norris 2 H. B. Rhodes Technology Manager KM 01095 - PLAINTIFF'S EXHIBIT 44 Comparison of Airborne Asbestos Concentrations - Canadian and California Asbestos Based Ceiling Texture Sprays H. B. Rhodes B. L. Ingalls Union Carbide Corporation Metals Division Niagara Falls New York June 24 1975 KMX 01996 SUMMARY AND CONCLUSIONS Short fiber asbestos from Canada and highly refined asbestos ' are produced in California by viscosity properties to a . The two sources differ in Union Carbide Corporation used to give key wide variety of coatings and laminating resins the form of the asbestos ore and in the processing used to manufacture the finished product These differences shift the fiber size distribution in the California product towards narrower finer and shorter fibers The object of this work was to compare the airborne asbestos fiber concentrations that occur during the field mixing and application of ceiling texture paints containing 2-5 levels of each of these types of asbestos Field samples were collected at two construction sites in California and were subjected to the following analyses 1. Standard OSHA counts at 400X by both Union Carbide and a certified industrial hygiene laboratory LFE Incorporated 2. Optical counts of all asbestos fibers longer than about one micron using phase contrast at 1000X 3. Transmission electron microscope counts at 1400X with fibers identifiebdy selected area electron diffraction The two types of asbestos compared showed borne asbestos concentrations in either the 1 to 5 the 5 micron range normally considered in the OSHA no difference in the micron size range or regulations airin KMX 01997 TABLE CONTENTS Section | SUMMARY AND CONCLUSIONS _ INTRODUCTION OBJECTIVE DESCRIPTION OF TEST OPERATIONS ~ SAMPLING AND COUNTING PROCEDURES RESULTS AND DISCUSSION ACKNOWLEDGEMENTS TABLES PPagePaagge e em 1 1 2 KMX 01998 INTRODUCTION Short fiber asbestos is used in a wide variety of coatings laminating resins to impart critical viscosity properties when these materials are sprayed and to prevent sag.during cure This asbestos mainly from Canada and the New Idria deposit in California and comes The Canadian asbestos occurs in nature as closely packed parallel in fibers formed in cracks the surrounding rock It is converted to the commercial product by a series of dry grinding screening and air classifi- cation operations The California asbestos occurs in the form of entangled fiber bundles compacted into flakes containing 50-75 asbestos Union Carbide who supplies essentially all of the California asbestos used in this type of specialty application uses a wet shearing and classification manufacturing process The combined effect of the different natural form and the different processing shifts the fiber size distributioinn the California Calidria Union Carbide products towards increased amounts of finer narrower and shorter fibers . OBJECTIVE The basic objective of this work was to make a direct comparison of Canadian and California Calidria airborne asbestos fiber concentrations during the mixing and spraying of ceiling texture paint The concentrations . of fibers both shorter and longer than 5 were examined DESCRIPTION OF TEST OPERATIONS Tests were carried out at two locations in Los Gatos CA. In each case ceiling texture formulations containing roughly the same amounts of Canadian or California Calidria asbestos were sprayed by the same under the same conditions The first series of tests was typical operator while the second was representative of of the small custom operator large production type procedures and equipment on In the first sequence the operator added four pound bags of dry spray texture paint containing % of 7M05 Canadian asbestos into the top of a small Spray Force sprayer containing about 80 gallons of water The mixed paint was pumped through a hose to a wand about 4 long with a nozzle the side of the tip Compressed air to atomize the liquid was , supplied through a second hose During spraying the operator walked slowly through each room with the _ nozzle pointed towards the ceiling and sweeping back and forth about 4-5 feet from the floor A second man designated as the wiper assisted in moving the hose and immediately removed any overspray on the walls with a scraper about 18 wide ft Approximately half of the ceilings 484 in a large single- story house were sprayed with the mixture containing Canadian asbestos Total time was about 12 minutes The tank was then washed out and four spraying California asbestos Calidria HPO instead bags of spray texture with % of of the Canadian were mixed and sprayed in the same way The mixture ran out and before the was completed two more bags were mixed Total area spraying covered was 650 ft2 KMX 01999 Personal samples were taken on the operator during each main mixing and during each spraying sequence The two bag supplementary mixing was not sampled The wiper was sampled during each spraying One area sample was taken in the opposite end of the house during the spraying of the Canadian containing material and the initial part of the California containing . spraying operation The second test sequence was run at another location in Los Gatos with a large mounted spray unit Four bags of dry spray texture containing * California asbestos Calidria HPO were added to the mixer which was already partially filled with the same blend The ceilings in complete house 1300 ftwere sprayed A bag blend of the same texture blend containing 2.5 Canadian 7M05 was then mixed and sprayed on the ceilings ofa second house These blends contained an additional pound of styrofoam and were thicker than that used in the first location There was some problem with the spraying of the Canadian containing material and working pressure was reduced from 120 to 70 psig Personal samples were collected on the mix and during each spraying sequence Personal wiper during each spraying spray operator during each samples were collected on the SAMPLING AND COUNTING PROCEDURES Throughout these tests simultaan ireso amu pls es on the same " operator were collected by the LFE Corporation and by Union Carbide Battery air pumps were used to obtaianll samples on Millipore mem- brane filters of 0.8 micron porosity Dust counting was carried out independently by both laboratories in accordance with OSHA Regulation using 1910.001 using In the Union the Bayer Zummaldaned Carbide counts the field contrast least Brown phase procedure area was 0.0062 mm and at least 100 fields were counted in each sample In addition to the regular OSHA counts Union Carbide read the samples for the mixing and spraying operator at 1000X under phase contrast illumination with oil immersion These counts were made immediately following the the standard OSHA counts and utilized same sample mount Fiber sizes down mm to about lu in length were counted Field area was 0.0009 , and at least 100 fields were counted in each sample Transmission electron microscope techniques were also used to measure the fiber size distributions for one spraying sample containing each type of asbestos For these counts the filter was carefully removed from the holder and cut in half with a scalpel It was then carbon coated and 8-10 sections selected randomly over the filter were placed in grid mounts ~ in diameter The Millipore filter was dissolved away with acetone Twenty squares in each mount were scanned at 1400X magnification The area of each grid square about 0.008 mm Any fibers found were photographed measured and checked . for structure by selected area electron diffraction at 15,000X * Laboratories LFE Corporation Environmental Analysis Laboratories 2030 Wright Avenue Richmond California 94804. The LFE industrial hygiene laboratoriys certified by the American Industrial Hygiene Association KMX 02000 RESULTS AND DISCUSSION The results of the standard OSHA type fiber counts by the two laboratories are listed in Table 1. The overall agreement between laboratories is excellent The Union Carbide results however are consistently a moderate amount higher These are industrial samples with low levels of asbestos _ fiber amid substantial amounts of background dust The Union Carbide numbers reflect a conscious effort to make certain that all particles which could possibly be asbestos were counted Some asbestos fibers were undoubtedly included in the results reported type been low The range of airborne fiber concentrations given in Table I for each of asbestos during the dry mixing and during the spraying operations have summarized in the table that follows As the data show the levels are for both operations The range of airborne concentrations for the two ~ types of asbestos overlaps in each operation tested There is clearly no difference between these types of asbestos for airborne concentrations of asbestos fibers longer than 5 Airborne Asbestos Fiber Concentration Fibers LONGER than 5u Dry Mixing of Spray Texture Spraying | UCC LFE UCC LFE Canadian Asbestos Grade 7M05 California Asbestos Calidria HPO 0.6-3.2 1.5-2.7 0.5-2.4 1.1-1.8 ' 0.8-1.6 0.5-0.9 0.3-0.7 0.2-0.6 at under The personal samples for the mixing and spraying operator in each set of tests were also counted 1000X phase contrast illumination using oil immersion At this magnification the operator was able to distinguish particles and to judge whether they met the D criteria down to lengths of approximately one micron The results are shown in Table II The regular OSHA counts at 400X from Table I have also been included for comparison of Compare first the concentrations of fibers longer than 5 microns as counted at 400 and 1000X The counts obtained at the higher magnification range from 1.3 to 2.6 times those at 400X and average a factor of 1.8 times Since more detail can be seen at 1000X it is reasonable that higher counts are obtained Considering the variability in this type counting particularly when applied to mixed dust samples like these the internal consistency found here is excellent KMX 02001 The data for the concentrations of fibers shorter Table II are summarized for each operation in the following by asbestos type than 5u given in table categorized Canadian Asbestos Grade 7M05 Airborne Asbestos Fiber Concentration Fibers SHORTER than 5u Dry Mixing of Spray Texture Spraying 1.6-10.9 5.7-7.4 California Asbestos Calidria HPO 5.0-5.7 2.3-3.5 Although the dry mixing results for the texture paint that contained Canadian asbestos show a substantial spread the average for the two tests is 6.2 fibers This is quite close to the range of 5.0-5.7 fibers found _ for the same operation with the texture paint containing the California asbestos In the spraying tests the material containing the California asbestos gave concentrations about half that of the Canadian material In view of the limited number of tests run and the uncertainties in counting procedures of this type the results are considered to be good evidence that the California asbestos does not have any greater tendency than the Canadian asbestos to yield finer fibers when dry mixed or sprayed The samples collected in the operator's breathing zone during the first set of spraying tests were also examined with transmission electron microscope at 1400X All particles with an D ratio greater than 3 were magnified to 15,000 photographed measured and checked for crystal structure identification with selected area electron diffraction in Table III The results are shown In general it was found that very few of the fibers seen gave electron diffraction patterns characteristic of chrysotile asbestos i.e. only 3 out of 26. Where patterns were obtained they came from the extreme tips of the particles This lack of pattern could be due to fibers being too thick for the beam to penetrate or because the resin binder had formed a coating Probably both factors contributed In order to avoid instrument contam- ination however no attemptwas made to burn away any coatings that may have been present : Visually it appeared that the majority of the fibers in listed Table III had the distinctive appearance of chrysotile asbestos If it is assumed that all of the fibers where the length was defined were asbestos KMX 02002 the corresponding airborne concentrations will be * Canadian Asbestos Grade 7M05 California Asbestos Calidria HPO Airborne Asbestos Fiber Concentration fibers | 7 SHORTER than 5 LONGER than 5u 0.13 0.15 0.22 0.11 It is immediately evident that these concentrations are an order lower than the optical counts This difference is at least in of magnitude resolution at both 1400 and 15,000X on the electron mpairctrodsuceopteo tWheithbetttheirs instrument it was easy to distinguish fibers from clumps and chunks of finely divided plastic and other solids the The key point however is that the concentrations for both types fiber size range are extremely low Considering of asbestos throughout fibers found there is no evidence of any the very small number of possible of asbestos in the tendency to produce difference between the two types fibers shorter than 5 KMX 02003 ACKNOWLDEGMENTS The authors wish to thank Dr. Kuldip for providing the electron microscopy data and assistance with the optical fiber counting Chopra to Mr. and Mr. Robert Robert Kennedy . Hallissy for KMX 02004